Photographic element



May 5, 19,42 L. s. BRooKL-:R 2,282,116

PHQTOGRAPHIC ELEMENT Filed March 1, 1940 2 sheets-sheet 1 rhode/vine.

ESL /E 6. 5. /QOOKER IN VENT OR A TTOR YS May 5, 1942 L. G. s. BROOKER f 2,282,116

PHOTOGRAPHIC ELEMENT -Filea Maron 1. 1940 2 sheets-sheet 2 F/cs. 5

f6/J5 6. 5.- 15H00/ 5@ INI/ENTOR Patented May 1942 PHOTOGRAPHIC ELEMENT Leslie G. S. Brooker, Rochester, N. Y., assigner toEast man Kodak Company, Rochester, N. Y.,

a corporation of New Jersey Application March 1, 1940, serial Np. 321,730 nl Great Britain April 14, 1939 9 Claims.

This invention relates to photographic elements having one or more silver halide emulsion layers containing sensitizing dyes which are nondifusing incharacter. More particularly, it relates to photographic elements having at least two silver halide emulsion layers superimposed, each of -which contains a non-diusing sensitizing dye of diierent spectral sensitivity.

In color photographic processes, itis common I to employ photographic elements comprising two `or more emulsions having different spectral sensitivities, coated on a single support. Thus, inv

monopack processes, the'color photographic element may comprise a support coated upon which is an emulsion layer sensitized to the red, upon which is coated an emulsion layer sensitized to the green, upon which is coated an emulsion layer which is sensitive to the blue. The emulsion layers may be separated by intermediate layers of a colloidal substance like gelatin. Or, in monopack processes, the color photographic element may comprise a support coated on one side of which is an emulsion layer sensitized to, the red, and upon the other side of which is coated an emulsion layer sensitized to the green, upon which is coated an emulsion layer which is sensitive to the blue. Or, in monopack processes, the color photographic element may comprise a support coated with an emulsion of the mixedgrain or mixed-emulsion type, i. e., in which two or more sets of grains of' a photo-sensitive silver salt, such as silver halide, having dierent spectral sensitivities are mixed together in a colloid medium, such as gelatin. Such a mixed-grain emulsion is, of course, in effect a mixture of emulsions having diierent spectral sensitivities. Or in bipack processes, the color photographic element may comprise a support coated with an emulsion layer which is sensitive to the greenV upon whiohis coated an emulsion which is sensitive to the blue, while the red sensitive layer is coated on a different support.

In all such color photographic elements,V the red-sensitive emulsion is `rendered sensitive to the red by incorporation of sensitizing dyes in Vthe emulsion; likewise the green-sensitive layer is rendered sensitive to the green by incorporation of sensitizing dyes in the emulsion; `whileI ordinarily no sensitizing dyes are incorporated inthe blue-sensitive emulsion, since the silver bromide emulsions ordinarily employed for such a purpose are sufficiently sensitive-to blue light. However a sensitizing dye which sensitizes to the blue may be incorporated in the blue-sensitive emulsion layer and, in fact, when employing silver' chloride emulsions as the blue-sensitive layer, sensitizing dyes are incorporated, in order to render the emulsion layer sensitive to about the same blue light to which a silver bromide emulsion is sensitive.

In practice, the sensitizing dyes present a considerable difilculty because there is a greater or lesser tendency for the dyes to diiluse from the emulsion vin which they are incorporated, into the adjacent emulsion. Diiusion of the sensitizing dyes from the green-sensitive layer into the blue-sensitive layer has provided an especially troublesome situation.

I have now found that the aforesaid difficulties of diiIusion can be overcome or at least greatly diminished by employing, as sensitizing dyes, dyes containing, as a substituent or addendum to the molecule of the sensitizing dye, a long-chain organic group. A- few sensitizing dyes containing a long-chain organic group are available and v while I have found that these available dyes do not diffuse to a great extent, I have also found that these available dyes are not strong sensitizers. Apparently, the presence of the long-chain organic group diminishes their sensitizing action. In the interest of obtaining dyes containing a long-chain organic group and which sensitize photographic emulsions strongly, I have found certain new merocyanine dyes.

It is an object oi' my invention, therefore, to provide a photographic element having onel or more silver halide emulsion layers, at least one of which'layers contains one or more sensitizing dyes which have a long-chain organic group as a substituent oraddendum to their molecule. A

further object is to provide a color photographic element comprising two or more silver halide emulsion layers having diil'erent spectral sensitivities, wherein at least one of the emulsion layers contains a sensitizing dye having a long-chain organic group, as a substituent or addendum to its molecule. A still further object is to provide a series of new sensitizing dyes which have a long-chain organic group as a substituent or addendum Ato their molecules. Another object is to provide a process for preparing such new dyes.

Other objects will appear hereinafter.

I have found that photographic sensitizing dyes containing a long-chain organic group of at least seven non-metallic atoms as a substituent, can be employed in practicing my invention. The atoms forming-the chain are advantageously from the group consisting of carbon atoms, oxygen atoms. sulfur atoms and nitrogen atoms. Where valence permits. non-metallic atoms such as hydrogen.

oxygen. sulfur, nitrogemhalogen or carbon atoms can be attached to the chain atoms. Most advantageouslytheatoms forming the chain are entirely carbon atoms and the atoms attached to the chain carbon atoms are hydrogen. Ciener-` ally speaking, a sensitizing dye containing a hydrocarbon group comprising a chain of at least seven carbon atoms is especially advantageously employed in practicing my invention. Typical long-chain groups are as follows:

o l Crn-CNi-cHf--CHi-III-i'J--CnrO nfPrimarypentadecyl CH3-4 CH2) is-CHa- The position in the sensitizing dye where the long-chain organic group is attached has a considerable effect on the sensitizing action of the dye, I have found. Thus, when the long-chain group is attached to the polymethine chain oi a polymethine sensitizing dye, the sensitizing power of the dye is ordinarily very considerably diminished. Likewisewhen the long-chain group is attached to one of the auxochromic atoms of a. sensitizing dye, as to one oi the auxochromic nitrogen atoms oi al oyanine dye, thus:

Lauryl the sensitizing power is ordinarily very considerably diminished. While such sensitlzing dyes of diminished sensitizing power are within the scope of my invention, I prefer to employ sensitizing dyes which have a long-chain organic group, and in which the sensitizing power is not greatly diminished.

Sensitizing dyes of the cyanine class, of the merocyanine class, of .the hemioxonol class and of the hemicyanine class for example, contain a. polymethine chain connecting two auxochromic atoms. In cyanine dyes, the two auxochromic atoms are both nitrogen atoms; in merocyanine dyes, the auxochromic atoms are oxygen (or suliur) and nitrogen; in hemioxonol dyes, the auxochromic atoms are oxygen (or sulfur) and nitrogen; and in hemicyanine dyes, the auxochromic .atoms are both nitrogen atoms. I have found that sensitizing dyes of the aforesaid classes containing. as a substituent, a long-chain organic group on a portion ot their molecules other than the polymethine chain or the auxochromic atoms, have not only a greatly diminished tendency to diiTuse, relative to many sensitizing dyes which do not contain a long-chain organic group substituent, but are very strong sensitizers, relative to sensitizing dyes having a long-chain organic groups, as a substituent on the polymethine chain or on the auxochromic atoms.

I have found new dyes of the merocyanine class which contain a long-chain organic group, as a substituent on other than the polymethine chainand on other than the auxochromic atoms, which show but a relatively small diminution of sensitizing power owing to the long-chain organic group. Such dyes can be represented by the following general formulas:

and

wherein A represents oxygen or sulfur, D represents a divalent organic group, such as a vinylene or a phenylene group for example. L represents a long-chain organic group substituent, n represents a positive integer of from one to three, Q represents the non-metallic atoms necessary to complete an organic heterocyclic nucleus, such l and Z represents the non-metallic atoms necessary to complete a. tive-membered heterocyclic organic nucleus, such as, a 2thio-2,4(3,5) thiazoledione (rhodanine) nucleus, a 2thio 2,4(3,5) -oxazoledione nucleus, a 2-thio2,4(3,5) imidazoledione (Z-thiohydantoin) nucleus, a 2,4-dithio2,4(3,5) thiazoledione, or a 2,4-dithio- 2,4(3,5) -imidazoledione nucleus, ior example.

I have found that the above formulated merocyanine dyes can be prepared by condensing a cyclammonium quaternary salt containing a -arylaminovinyl group (advantageously an acylated p-arylamnovinyl group) in the alpha or gamma position, i. e. one of the so-called reactive positions, with a compound oi the iollowing formula:

wherein A represents oygen or sulphur, L represents a long-chain organic group containing a chain of at least seven members each of which is composed of non-metallic atoms and Z represents the non-metallic atoms necessary to complete a flve-membered heterocyclic organic nucleus, such as a 2thio-2,4(3,5) -oxazoledione nucleus. a 2thio2.4(3,5) -thiazoledione nucleus. a. 2thio2,4(3,5) -imidazoledione nucleus or a thiopyrazolone nucleus for example. As quaternary salts, the albi halides, are advantageously employed. The condensations are advantageously effected in the presence oi' a basic condensing agent. Sodium and potassium acetates are suitable basic condensing agents, and when these agents are employed, condensations are advantageously carried out in the presence 'of acetic anhydride. Strong organic bases (i. e. organic bases having a dissociation constant substantially greater than that oi' pyridine), particularly tertiary organic bases, like triethylamine, tributylamine or N-methylpiperidine, are advantageously employed as condensing agents. When these strong organic bases are employed, the condensations are advantageously carried out inthe presence of alcohol solvents, such as alcohols oi the formula CnHznHOH wherein n represents a positive integer o'f from one to four. Heat accelerates the formation of my new dyes.

The following examples are oiered by way of illustration of the preparation o! the above formulated new merocyanine dyes. Theseexamples are not intended to limit my invention.

2.3 g. 4(1 mol.) of 3-n-primaryheptyl-rhodanine,

4.34 g. (l mol.) of l-(p-acetanilido-vinyll-benzoxazole ethiodide and 1.0 g. (l mol.) of triethyl- -am'ine were placed in' 15 cc. of absolute ethyl to 131 C. The dye. is a powerful sensitizer of gelatino-silver-bromide emulsions for the green, its effect extending to 600'mu with a maximum at 540 mu.

In a similar manner to that illustrated in the foregoing example, 3-n-primaryoctyl-rhodanine, B-n-primarydecyl-rhodanine, and 3-'n-prmarylauryl-rhodanine can be condensed with l-(- acetanilido-vinyl)-benzoxazole ethiodide to yield having a melting point oi' lll-112 C. and sensitizing a gelatino-silver-'bromide emulsion out to about 600 mu with a maximum at about 555 mu and vr5- (2-ethyl-1(2) -benzoxazolylidene) ethylidene]-3-n-prlmarylauryl-rhodanine in the form 6.8 s. methiodide, 4.6 g. (l mol.) of 3-n-primaryheptylrhodanine and 2.2 g. (1.1 mol.) of triethylamine were placed in cc. of absolute ethyl alcohol. 'I'he mixture was heated on a steam bath, under reflux, for about 30 minutes. The mixture was then chilled to 0 C. and the dye which separated was filtered oil, washed with methyl alcohol and dried. After tworecrystallizations from methyl alcohol, the dye was obtained as amber-colored crystals melting at to 123 C. 'I'he dye is a powerful sensitizer ot gelatino-silver-bromide emulsions for the green, its eiect extending to 580 mu with a maximum at 530 mu.

s=c N-cim primar'yheptyl 1- 2.6 g. (l mol.) of S-n-primaryheptyl-l-phenyl-.

filtered oi. After four recrystallizations from methyl alcohol, it was obtained as brownish needles having a blue reilex and melting at 178 to 179 C. The dye is a strong sensitizer i'or gelatino-silver-bromide emulsions, its effect extending@ 560 mu with a maximum at 530 mu.

In place of S-n-primaryheptyl-l-phenyl-2- thiohydantoin, there may be substituted in the above example, 3-n-heptyl-2-thiohydantoin to give the dye 5-[2-ethyl-l(2) benzoxazolylidene ethylidene] -3-n primaryheptyl-Z-thiohydantoin inthe form of orange crystals having a melting point of 207-209" C. with decomposition, and sensitizing a gelatino-silver-bromide emulsion .out to about 560 mu with a maximum sensitivity at about 525 mu; 3-n-primarynonyl-1-phenyl-2- thiohydantoin to give the dye 5[(2-ethyl1(2)- benzoxazolylidene) ethylidenel 3 n primarynonyl-1-phenyl-2-thiohydantoin in the form of orange crystalline needles having a melting point of 179181 C. and sensitizing a gelatinofsilverbromide emulsion out to'about 570 mu with a oi' red crystalline needles with blue reflex having a melting pointof 109ll0 C. and sensitizing a gelatino-silver-bromide emulsion out to about 580 mu with a maximum sensitivity at about 560 mu respectively.

maximum sensitivity at about 530 mu; and 3-nprimarydecyl-l-phenyl-2 thiohydantoin to give the dye 5[(2 ethyl 1(2) benzoxazolylidene) ethylidene] -3-n-primarydecyl-lphenyl-2 thiohydantoin in the form of yellow Icrystals having a melting point of 172 C. and sensitizing a gelatino-silver-bromide emulsion out to about 565 mu with a maximum sensitivity at about 530 mu.

(l mol.) oi' 2anilidovinylthiazoline -V bath, under reflux, for l minutes.

4 ExAMPLE 4.---[4-(2-eth11l 1(2) benzomazolyl idene) butenyldenel-3-n-lauryl-rhodanine 2.3 g. (l mol.) of 1-(4-acetanildo-Am-butadienyD-benzoxazole ethiodide," 1.5 g. (1 mol.) of 3-n-laurylrhodanine and 0.5 g. (l mol.) of triethylamine were placed in 15 cc. of absolute ethyl alcohol. The mixture was heated on a steam The mixture took on a deep purplecolor. The mixture was chilled to 0 C. The dye which separated was filtered off. The residue on the Illter was extracted with 100 cc. of boiling methyl alcohol. 'I'he undissolved residue was then twice recrystallized from methyl alcohol and the dye was obtained as a mat of greenish crystals melting at 91 to 93 C. The dye sensitized a gelatino-silver-bromide emulsion from about 620 mu to about 670 mu with a maximum at 650 mu.

Instead of 3-n-laurylrhodanine, there may be employed in the above example, 3-n-heptylrhodanine to give the dye 5-[4(2-ethyll(2) benzoxazolylidene) butenylidene] 3 n heptylrhodanine in the form of minute blue crystals having .a melting point of ITI-129 C. with decomposition, and sensitizing a gelatino-silverbromide emulsion from about 540 mu to 690 mu with a maximum sensitivity at about 660 mu.

EXAMPLE 5.-5 (2 ethyl- 1(2)- benzothiazolyli- 1.15 g. (1 mol.) of 3-n-heptylrhodanine and 2.0 g. (1 mol.) of 1phenylmercaptobenzothiazole ethiodide were heated to reflux in ccs. of absolute ethyl alcohol and 0.53 g. (1.05 mol.) of vtriethylamine added withv shaking. 'The mixture was then refluxed for about minutes, followed by chilling for several hours at about C. The crude crystals which formed were filtered oi, washed with methyl alcohol, and purified by recrystallization twice from methyl alcohol. -The dye thus obtained had a melting point of 1'74-175 C. and sensitized a gelatinosilver-chloride emulsion to about 505 mu with maximum sensitivity at about 470 mu.

EXAMPLE 6.-5- [4- (2-ethyl-1 (2) -benzothiazolylidene) butenylidene] 3-nheptylrhodanine of 3-n-heptylrhodanine, and 0.5 g. (1 mol.) of trlethylamine were heated to reilux for 10 minutes in 20 ccs. of absolute ethyl alcohol. The mixture was then chilled and the crude dye crystals which formed were illtered ofi, washed well with methyl alcohol and subjected to two recrystallizations from a mixture o! pyridine and methyl alcohol. The puried dye'obtained as minute blue crystals had a Amelting point of 161- 163 C. with decomposition, and sensitized a gelatino-silver-bromide emulsion from about 655 mu to about 710 mu with maximum sensitivity at about 690 mu.

In place of 3-n-heptylrhodanine, there may be substituted I3-n-octylrhodanine rin which case there is obtained the dye 5-[4-(2-ethyl-l(2) benzothiazolylidene) butenylidene] 3 n octylrhodanine in the form of a mat of minute blue crystals having a melting point of 161-163" C. with decomposition, and sensitizing a gelatinosilver-bromide emulsion from about 620 mu to 715 mu with maximum sensitivity at about 690 EXAMPLE '1.-5-u2-ethuz 1 (2) benzmrmflzozyzidene) -ethz/lidene] -S-n-heptyl-I -phenyl-Z-thiohydantoin 2.9 g. (l mol.) of 3-n-heptyl-1-phenyl-Z-thio- EXAMPLE 8.-5-[4-(2-ethyZ-1(2) -benzothiazolylidene) butenylidenel-S-n-heptyl 1 phenyl 2- thiohydanton A mixture of 2.9 g. (1 mol.) of 3-n-heptyl-lphenyl-2-thiohydantoin, 4.8 g. (l mol.) of 1-(4- acetanilidoAl-butadienyl)-benzothiazole ethiodide, 1.0 g. (l mol.) of triethyiamlne, and 30 ccs. of absolute ethyl alcohol was-allowed to stand at room temperature for a period of about 17 hours. At the end of this time the reaction mixture had developed a blue color and some crystals had separated out of solution. The mixture was then chilled and the crystals ltered oil, washed with methyl alcohol, and recrystallized from methyl alcohol, then from absolute ethylv alcohol, and finally from ethyl alcohol. The purined dye obtained in the' form of a dark green felt had a melting point of 18S- oxazoledione and 2.00 g. (1

190 C. and sensitized a gelatina-silver-bromide emulsion from about 540 mu to about '115 mu with maximum sensitivity at about 690 mu.

.at C. The crude crystals which formed were filtered oil, washed with methyl alcohol, and recrystallized twice from methyl alcohol. The puried dye obtained in the form of a pale yellow solid had a melting point of 'I3-74 C. and sensitized a gelatine-silver-chloride emulsion up to 445 mu with maximum sensitivity at about 435 mu.

A mixture of 2.15 e'. (l mol.) of 3-n-heptyl-2-- thio2,4(3,5) oxazoleclione 4.35 g. (l mol.) of 1- (-acetanilido-vinyl) -benzoxazole ethiodide, 1.01 g. (1 mol.) of triethylamine, and 50 ccs. of absolute ethyl alcoholwas heated under reux on a steam bath for a period of minutes. At the end of this time, the reaction mixture was chilled and` the crystals which formed were iltered off, washed with alcohol, and recrystallized two times from absolute ethyl alcohol. The puriiied dye obtained as uiy yellow needles had a melting.` point oi 19T-498 C. and sensitized a gelatine-silver-hromide emulsion up to 555 mu with maximum sensitivity at about 525 mu. A

ln place oi' '..Zi-n-heptyl-Z-thio-2A(3,5) -oxazoledione, there may be substituted in the above C. and sensitizing' 2.15 g.' (1 mol.) of 3nheptyl2thio2,4(3,5) oxazoledione, 3.50 g. (1 mol.) of 2--anilidovinyl thiazoline methlodide, 1.01 s. (1 mol.) of triethylamine,l and ccs. of absolute ethyl alcohol were heated'to reflux for a period of 20 minutes.

. The reaction mixture was then chilled, and the dye crystals which formed were nltered oil. washed with methyl alcohol, and recx'ystallized three times from methyl alcohol; The purified dye obtained in the form of yellow akes had a v melting point. oi 147-149" C. and sensitized a gelatina-silver-chloride emulsion to 520 mu with maximum sensitivity at about 500 mu.

mol.) of l-(fl-acetanilido-Al-butadienyhbenzothiazole ethiodide, 1.05 g. (1 mol.) 3nheptyl2thio-2,4(3,5) r-oxaitolediona 0.5 g. (1 mol.) of triethylamine, and 15 ccs. of absolute ethyl alcohol were heated together under reux l 2.4 g. (l

for a period of about 10 minutes. The reaction mixture was then chilled, and the crystals which formed wee collected on a filter and washed with methyl alcohol. The solid was then extracted with hot methyl alcohol, the extract chilled, and the crystals which formed were recrystallized once more from methyl alcohol. The dye ob tained in the form of blue crystals had a melting point oi? lidi-143 C. and sensitized a lgelatinesilver-bromide emulsion from about 550 mu to about 605 mu with maximum sensitivity at about 655 mu.

.4i mixture of 0.75 a. (l mol.) `of 3nlaury1 rhodanine, 1.11 g. (1 mol.) of 4-(u-acetanilidovinyl) quinoline ethiodide, 0.25 g. (1 mol.) of triethylamine, and 30 ccs. of absolute ethyl alcohol was heated under reiiux for a period of about 20 minutes. Dye separated from the hot reaction mixture. After chilling, the crystals were iiltered oil', washed with cold methyl alcohol, boiled with 75 ccs; of methyl alcohol, and the insoluble residue purified by two recrystallizations from a pyridine-methyl alcohol mixture. The dye obtained in the i'orm of blue crystals had a melting point oi' 157-158" C. and sensitized a gelatina-silver-bromide emulsion.

A mixture of 0.70 g. (l mol.) of 3-n-lauryl-2- thio2,4(3,5) -oxazoledione, 1.11 g. (1 mol.) of 2- (w-acetanilido-vinyl) quinoline ethiodide, 0.25 g. (1 mol.) of triethylamine, and 15 ccs. of absolute ethyl alcohol was heated under reilux for a period of about 20 minutes. The reaction mixture was then chilled, and the crystals lwhich formed. were collected on a filter, washed repeatedly with hot methyl alcohol, and recrystallized from a pyridine-methyl alcohol mixture. The dye obtained in the form of a reddish felt had a melting point of 176-l77 C. and sensitized a gelatino-silver-bromide emulsion.

' A mixture of 1.46 g. (1 mol.) of ethylene-bis (3.3'rhodanine), 4.34 g. (2 mol.) of l-(-acetanilido-vinyl) benzoxazole ethiodide, 1.01 g. (2 mol.) of triethylamine, and 200 ccs. of absolute ethyl alcohol was heated under reflux for a period of about 20 minutes. The reaction mixture was then chilled, and the dye crystals which formed were ltered off, washed with methyl alcohol, and purified by recrystallizations from a pyridine-methyl alcohol mixture. The dye obtained in the form of a scarlet powder had a melting point greater than 300 C. and sensitized a gelatino-silver-bromide emulsion to about 610 mu with maximum sensitivity at about 565 nai-benzoxazozyziaene) ethyzidene] moa 0.47 g. (l mol.) of decamethylenebis(3,3 rhodanine), 1.09 g. (2 mol.) of 1-(-acetanilidovinyl) benzoxazole ethiodide, 0.40 cc. (2 mol.) of triethylamine, and 20 ccs. of absolute ethyl alcohol were heated under redux for a period of about 20 minutes. The reaction mixture was then chilled, and the crystals which formed were filtered oil', washed with methyl alcohol, and puried by two recrystallizations from a solvent mixture of pyridine and methyl alcohol. The dye obtained in the form of a reddish-brown powder had a melting point of l64-166 C. and sensitized a gelatino-silver-bromide emulsion out to about 570 mu with maximum sensitivity at about 550 mu.

EXAMPLE 17.--3-1n-hepty1rhodanine '7.6 g. (1 mol.) of carbon disulfide was added dropwise with stirring to a mixture of 10.5 g. (l mol.) of n-heptylamine and 6.0 g. of potassium hydroxide in 150 ccs. of water. The reaction proceeded with the evolution of heat. After a period of about 30 minutes, there was added with stirring 9.5 g. (l mol.) of chloracetic acid 'neutralized with sodium carbonate in 100 ccs. of water, and the stirring continued for about one hour. The reaction mixture was then allowed to stand for 24 hours at room temperature, when it was acidifled with sulphuric acid to litmus paper, chilled to 0 C.- for a period, and theyellow fatty mass which formed `was filtered ofi, dissolved `in benzene, and driedl by distillation of the solvent. The product obtained in this manner was used for dye condensations without further purification.

In a manner generally similar to that above described, but using the corresponding octylamlne decylamine, and laurylamine compounds, 3-n-octylrhodanine, 3ndecylrhodanine and 3- n-laurylrhodanine may be prepared.

Exnnu: 18.-3-n-heptul-2-thio-2A (3,5 oxazoledione A mixture of 12.1 g. (l mol.+l00% excess) of n-heptylamine. 10.5 g. (l mol.) of acetamidocarbothiolonglycollic acid, 2.8 g. of 85% potassium hydroxide, and 150 ccs. of water was stirred Aat room temperature for a period of about 51/2 In a manner generally similar heated under reflux for about minutes, the

alcohol solvent evaporated for the most part` and the residue treated with 5 ccs. of water and l then with l0 ccs. of concentrated hydrochloric acid. A yellow precipitate was formed at once.

to the above de lscribed process, but using the corresponding After cooling-the reaction mixture, the solid was -flltered oii, 'washed with water, suspended in 60 ccs. of 12% hydrochloric. acid,'and the suspension heated at 95 C. for about two hours. The

suspension was then chilled, and the solid iil. 5

tered 01T, washed with water, and recrystallized from ligroin. The product obtained as pale yellow plates had a melting point of 90-92? C.

-. dantoin Amixture of 6.1 g. (1 mol.) of nonyl isothiocyanate and 5.9 g. (1 mol.) of N-phenylglycine ethyl ether was heated in an oil bath at 185- l90 C. for a period of about four hours. The 15 reaction mixturel was then distilled under reyduced pressure and the fraction boiling at 218220 C. at 1 mm. pressure was recrystallized twice from petroleum ether. The purified .product had a melting point of 35-389 C..

20 If the nonyl isothiocyanate is replaced in the v15.2 g. (2 mol.) of carbon disulfide was added In place of .n-heptylamine in the above example, there may be'substituted an equivalent` quantity of n-nonylamine, in which case the compound n-nonylisothiocyanate is obtained in the fraction having a boiling range of 12'?-I l29 C. under 10 mm. of pressure.

EXAMPLE 23.--n-deoylisothcyanate A mixture of 5.0 g. .(1 mol.) of 'sym-di-ndec 0 ylthiocarbamide and 5.0 g. of phosphorous pentoxide was heated gently over a free'iiame for about minutes. The temperature was then raised suiliciently to distill the n-decylisothiocyanate formed at normal pressure. The fraction boiling in a range F75-250 C. was used for the 'preparation of 3-n decyl1phenyl2thio hydantoin without further purincation.

My invention is directed to any photographic element having one or more silver halide emulsion layers, but more particularly `to any color photographic element comprising two or more photographic silver halide emulsions which have diiierent spectral sensitivities, and', still more particularly to the ordinary 'gelatino-silverbromide emulsions ordinarily employed in lthe preparation of color photographic elements. Ac-

'cording to my invention, I incorporate in the emulsion to be sensitized for the red, one or more of the non-diffusing dyes which sensitize for the with stirring over a 15 minute period to'a mX- 30 red, in the emulsion to .be sensitized for the ture of 6.0 g. 1 mol.) ofA ethylene-dlannne and grgn, VV(mevr. more of the non digusing dyes 11.2 g. (2 m01.) .0f 85% pOtaSSlllmhydlOXlde 111'" "which sensitize for the green, etc. The dyes are 200 ccs. of water, and stirring continued for 3 hours. At the end of this time; a. solution of 18 g. (2 mol.) of chloracetic lacid'neutralized with 35 10.6 g; (l mol.) of sodiumicarbonate in loonccs. 'of water wasI added tothe reaction mixture. After standing at room temperature with occasional shaking for about 18 hours, the mixture wasacidied to litmus paper with dilute sul- ,4b

phuric acid. The yellow, tarry product thus obtained solidified upon washing with water and ether, after which it was filtered off, washed well with water, then with'methyl alcohol, and e recrystallized twice from acetic acid.- The purified product obtained as straw-colored crystals 45 EXAMPLE 22.-1i-hcptylisothiocilanate 25.4 g. (A1 mol.) of carbon disulfide was added dropwise with stirring to a mixture of 29.8 g. (1 55 mol.) of n-heptylamine and-41 ccs. of 26% ammonia solution. The reaction took place with an evolution of heat, during which time the ammonium n-heptyl dithiocarbonate separate from solutionin the form of a gel. After minutes, 60

the reaction mixture was.diluted with water until -the precipitate dissolved, when 92.2 g. (1 mol.) of lead nitrate dissolved in 200` ccs. of water was added. A light brown precipitate,

into"a1receiverl containing 10 cc. of dilute sulohuric acid andthe distillate extracted several aimes with ether.- After drying over `calcium zhloride, the solvent was removed from the distillate by evaporation, -a'nd the residue fractioned under lreduced pressure.L 'I he product vas isolated in the-fraction having a boiling range of 112113 C. at 13 nun. pressure.

the compound degamethylene-e advantageously incorporated in the washed. finished emulsions prior .to coating the emulsions on a support. Ordinarily, from 3 to 30 mg. of the sensitizing dye per liter of ordinary gelatino-silver-bromide emulsion (about grams' of silver halide per liter of emulsion) suiilces to givethe optimum sensitization attainable with these non-diffusing sensitizers, although larger or smaller quantities canhe employed. It is, of l ported.` vThe optimumconcentration (i. e. the

concentration at which optimum sensitization is attained) for a sensitizing dye on a particular emulsion can be readily determined in a manner well known to those skilled in'the art, by measuring the sensitivity of a series of emulsions containing diierent concentrations of the sensitizing dye.A

'I'he dyes are advantageously incorporated in the emulsions in the form of solutions in appropriate solvents. Methanol has proven satisfactory as a solvent forthese' non-diffusing dyes. Ethyl alcohol or acetone can also be use d. The dyes should be thoroughly incorporated in the emulsion by stirring the emulsion during incorporation of the solution of the (we. turning black, of lead sulfide formed immedif ately.V Themixture was then steam distilled added with stirring to .1ooo ccs. of a nowame gelatino-silver-halide emulsion, and stirring contlnued until the dye'is thoroughly incorporated. The so-prepared emulsions can then be. utilized .75 in the preparation of color photographic ele- 3-n-lauryl-rhodanine.

and typical color photographic elements comprising two or more emulsions having diilerent sion containing one of my new merocyanine sensitizing dyes. In Fig. l, the curve depicts the sensitivity of an ordinary gelatino-silver-chloride emulsion containing '5-(2-ethyl1(2) -benzothiazolylidene)-3-n-heptyl-rhodanine. In Fig. 2, the curve depicts the sensitivity of an ordinary gelatino silver bromide emulsion containing 5 [(2 ethyl- 1(2) -benzoxazolylidenw ethylidene]-3-n-primaryheptylrhodanine. In Fig. 3, the curve depicts the sensitivity of an ordinary gelatino-silver-bromide emulsion containing 3- (n-primaryheptyl) i (3-methyl-2 (3) -thiazolinylidene)-ethylidenel-rhodanine. In Fig. 4, the curve depicts the sensitivity of an ordinary gelatino-silver-bromide emulsion containing 5-[4- (2-ethyl- 1(2) -benzoxazolylidene) butenylidenel In Fig. 5, the curve depicts the sensitivity of an ordinary gelatinosilver-bromide emulsion containing 5-[`(2ethyl- 1(2) benzoxazolylidene) ethylidenell B-n-primaryheptyl-l-phenyl-Z-thiohydantoin. In Fig. 6, the curve depicts the sensitivity of an ordinary gelatino silver bromide emulsion 5[ (2-ethy1- 1 (2) benzothiazolylidene) -ethylidenel -3 -n-heptyl-l-phenyl-Z-thiohydantoin. In Fig. '7, the curve depictslthe sensitivity of an' ordinary gelatino-silver-bromide emulsion containing 5-[4- (2 ethyl 1(2) ben'zothiazolylidene) butenylidene] 3 n heptyl-2-thio-2,4(3,5) -oxazoledione In Fig. 8, the curve depicts the sensitivity of an ordinary gelatino-silver-bromide emulsion containing 5 2 ethyl 1(2) benzoxazolylidene) edione.

Still further illustrations of my new non-diffusing sensitizing dyes, their application and spectral sensitivities in ordinary gelatino-silverhalide emulsions could be given, but the foregoing will suiiice to teach those skilled in the art the claims. f

What I claim as my invention and desire to be secured by Letters Patent of the United States is: v

1. A photographic element comprising a photographic silver halide emulsion which is sensitized with a sensitizing dye characterized by one of the following two formulas:

' vselected from the group consisting of uve-memes.

2,289,116 ments in a manner well known to those skilled l in the art. Typical color photographicprocesses wherein A represents an atom selected from the group consisting of oxygen'and sulphur atoms,

ID represents a radical selected from the group consisting of vinylene and phenylene groups, n represents a positive integer of from one to three, L represents a long-chain organic group comprising a chain ofat least seven non-metallic members, Q representsthe non-metallic atoms necessary to complete a heterocyclic nucleus selected from the group consisting of live-membered and six-membered heterocyclic nuclei, R represents an alkyl group, and Z represents the non-metallic atoms necessary to complete a 2-thio-2,4(3,5) -thiazoledione nucleus, a 2-thio- 2,4(3,5)imidazoledione nucleus. and a .2-thio- 2,4(3,5) -oxazoledione nucleus. l

2. A photographic element comprising a photographic silver halide emulsionsensitized with a sensitizing dye characterized by the following formula: l

wherein A represents an atom selected from the group consisting of oxygen and sulphur atoms, L represents a long-chain organic group compnsinigV :ar/chain'` of at leastV seven non-metallic members, Q represents the non-metallic atoms l necessary to complete a heterocyclic nucleus bered and six-membered heterocyclic nuclei, R represents an alkyl group, and Z represents the non-metallic atoms necessary to complete a 2-thio-2,4(3,5)thiazoledione nucleus, a 2-thio- 2,4(3,5)imidazoledione nucleus, and a 2-thio- 2,4(3,5) -oxazoledione nucleus. 1

- 3. A photographic element comprising a photographic silve/r halide emulsion sensitized with a sensitizing dye characterized by the following formula:

wherein, L represents a long-chainprganic group comprising a chain of at least seven non-metallic members, Q represents the non-metallic atoms necessary to complete' a heterocyclic nucleus selected from the group consisting of five-membered and six-membered heterocyclic nuclei, R represents an alkyl group, and Z represents the non-metallic atoms necessary to complete a 2- thio-2,4 (3,5) -thiazoledione nucleus.

4. A photographic element comprising a photographic silver halide emulsion sensitized with a sensitizing dye characterized by the following formula:

wherein, L represents a long-chain organic group comprising a chain of at least seven non-metallic members, Q represents the non-metallic atoms necessary to complete a heterocyclic nucleus selected from the group consisting of five-membered and six-membered heterocyclic nuclei, R represents an alkyl group, and Z represents the non-metallic atoms necessary to complete a 2thio-2,4(3,5) -lmidazoleidione nucleus.

5. A photographic element comprising a photographic silver halide emulsion sensitized with a sensitizing dye characterized by the following formula:

wherein, L represents a long-chain organicv group comprising a chain of at least seven non-metallic members, Q represents the non-metallic atoms necessary to complete a heterocyclicnucleus selected from the group consisting of ve-memsaid long-chain organic group being attached to h the dye at a position other than the polymethine chain and the auxochromic atoms.

7. A photographic element comprising Aa photographic silver halide emulsion which is sen'sitized with a sensitizing dye characterized by the following formula:

wherein L represents a. long-chain hydrocarbon group comprising a chain of at least seven carbon atoms, Q represents the non-metallic atoms necessary to complete a benzoxazole nucleus, R

represents an alkyl group selected from the group consisting of methyl and ethyl groups, and Z represents the non-metallic atoms necessary to complete a 2-thio-2,4(3,5) -thlazoledione nucleus.

8. A photographic element comprising a photographic silver halide emulsion which is sensitized with a sensitizing dye characterized by the following formula:`

wherein L represents a long-chain hydrocarbon group comprising a chain of at least seven carbon atoms, Q represents the non-metallic atoms necessary to complete a benzoxazole nucleus, R represents an alkyl group selected from the group consisting of methyl and ethyl groups, and Z represents the non-metallic atoms necessary to complete a 2-thio2,4(3,5)-oxazoledione nucleus.

9. A photographic element comprising a photographic silver halide emulsion which is sensitized with a sensitizing dye characterized by the 4 following general formula:

wherein L represents a long-chain hydrocarbon group comprising'a chain of 4at least seven carbon atoms, Q represents the nonlmetallic atoms necessary to complete a benzoxazole nucleus, R represents an alkyl group selected from the group consisting'. of methyl and ethyl groups, and Z represents the non-metallic atoms necessary to complete .a 2thio-2,4(3,5)-imidazoledione nucleus.

LESLIE G. S. BROOKER. 

